TY  - JOUR
A1  - Schairer, Patrick
A1  - Wagner, Stephan
A1  - Geidel, Ekkehard
T1  - An experimental introduction to basic principles of the interaction of electromagnetic radiation with matter
JF  - World Journal of Chemical Education
N2  - To understand basic principles about the interaction of electromagnetic radiation with matter is often a challenge in chemical education due to the difficult theoretical background of this topic. The present contribution therefore offers an experimental based introduction into the basic principles of UV/Vis spectroscopy following a three-step strategy. The starting point is to construct a simple self-built spectrometer working within the visible range of light. Learners can explore the most important components of such a device and understand their functions without previous knowledge. In a second step, emission spectra of different common light sources are investigated and compared. Finally, spectroscopic experiments are suggested for chemical education such as the qualitative detection of cations and the quantitative analysis of the dye carmine in food. This context-based introduction links chemical applications with the everyday life. It can be presumed that this way, learners are provided an easier access to radiation-matter interaction.
KW  - UV/Vis spectroscopy
KW  - low-cost spectrometer
KW  - flame test
KW  - quantitative analysis
KW  - carmine
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-175811
VL  - 6
IS  - 1
ER  - 
TY  - JOUR
A1  - Gräb, Patrick
A1  - Geidel, Ekkehard
T1  - Spectroscopic studies of food colorings
JF  - World Journal of Chemical Education
N2  - In chemical education, it is often a challenge to understand the basic principles of spectroscopic techniques due to missing connections to the real world. Therefore, the present contribution offers context-based applications of UV/Vis spectroscopy for analytics of food colorings with which learners can improve their skills regarding this method. The spectroscopic determination of food colorings seems to be a promising approach due to the long tradition and omnipresence of dyes in supermarket products. The therefor-required spectral data for commonly used dyes are provided for educational usage. Qualitative and quantitative analytics of food colorings in four different lemonades and chocolate beans have been used to introduce learners to important analytical techniques like sample preparation or elimination of confounding factors. These analytics also display the limitations of the method in the visible range of light in the case of tartrazine and curcumin. By applying Lambert-Beer-Bouguer’s Law in different variations, typical calculations of concentrations can be studied in quantitative analyses. The studied food samples demonstrate the different usage of food colorings depending on the country of sale. Finally, a 3D-printable low-cost photometer suitable for the discussed quantitative analytics in educational contexts is presented.
KW  - UV/Vis spectroscopy
KW  - quantitative analysis
KW  - food colorings
KW  - context-based teaching
KW  - low-cost photometer
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-201908
VL  - 7
IS  - 2
ER  -